1. Field of the Invention
The present invention relates to a method of manufacturing a single crystal Si film, and more particularly, to a method of manufacturing a single crystal Si film that can be formed on a substrate which is sensitive to heat.
2. Description of the Related Art
Poly crystalline silicon (poly-Si) is applied to various electronic devices, such as flat display devices and solar cells, due to its high mobility compared to amorphous silicon (a-Si). However, poly crystalline silicon has inferior mobility and homogeneity to single crystal silicon.
Single crystal silicon is especially useful in a system on panel (SOP) structure in which a system is formed directly on a display panel. The mobility of single crystal silicon is greater than 300 cm2/Vs. High quality switching devices for display devices can be obtained from single crystal silicon.
A critical factor in manufacturing single crystal silicon is the limitation of temperature. That is, the manufacturing process can not be performed at a temperature greater than that which the glass or plastic base material can withstand.
The smart-cut method of manufacturing a silicon on insulator (SOI) wafer includes an annealing process at a temperature greater than 1000° C. This method comprises coating an oxide film onto an initial bare wafer by thermal oxidation, forming a boundary layer using a hydrogen dopant by implanting hydrogen ions H+underneath the surface of the wafer, bonding the wafer to a substrate, forming silicon on the substrate by separating the boundary layer, and annealing.
The thermal oxidation is performed at a temperature of greater than 900° C., and the annealing is performed at a temperature of up to 1100° C. The high temperature processes may deform the substrate. The conventional method of manufacturing the SOI wafer limits the use of materials for the substrate and gives a thermal shock to the selected material. Therefore, obtaining the desired performance from silicon is difficult.